Radiant floor heating underlay board



FIG. 1 is a front perspective view of the radiant floor heating underlay board in accordance with the subject design;

FIG. 2 is a front elevational view of the radiant floor heating underlay board of FIG. 1;

FIG. 3 is a cross-sectional view of the radiant floor heating underlay board of FIG. 1, taken along line 3-3 indicated in FIG. 2;

FIG. 4 is a top view of the radiant floor heating underlay board of FIG. 1;

FIG. 5 is a right side view of the radiant floor heating underlay board of FIG. 1;

FIG. 6 is a rear elevational view of the radiant floor heating underlay board of FIG. 1;

FIG. 7 is a bottom view of the radiant floor heating underlay board of FIG. 1; and,

FIG. 8 is a left side view of the radiant floor heating underlay board of FIG. 1. 

CLAIM The ornamental design for a radiant floor heating underlay board, as shown and described. 